You are not a fat, old, balding guy who is losing his mind. You are an experienced, distinguished, full sized car repair artist. Always enjoy your videos
@@ThecardoctorTV I have a 2000 Chevy half ton 5.3 l that stumbling around showing p0300 multiple misfires I also have a code in the computer Bank 1 and 2 we're not working on the oxygen sensors. So O2 sensors will call these these trucks to stumble real bad like they're misfiring?
@@brt-jn7kg the o2 sensors measure the oxygen as you can imagine. So the truck and give the right air to fuel ratio. If they are not working then your engine doesn’t know how much fuel to send
Great heads up!!!! A buddy and myself pulled an 09 denali 6.0 that had oil leaks everywhere. When we installed it and finished it off it was running terrible (on odd bank) and we werent sure why... P0304. We went after # 4 no coil operation. Checked fuses power supply etc. Found it was the whole bank out. I figured I would google it ( yeah right! Who else has had this problem...nobody) Your video popped right up. It saved me hours of diag time. Went right to it found a broken wire, fixed it, cleaned and tightened the ground....Done! Thank You for putting this out. When you dont have a scanner or wire schematics life can suck. You helped me avoid the suck.
I have watched just three of your videos after finding you on TH-cam and all three vids fixed the problem I was having. Thank you ever so much for blowing up my parts cannon. You rock Tim!
'...and you burn yourself just like that...' I finally found this video on the goose chase of fixing my p0300 trouble on an '01 Silverado. This was a very helpful video and a lot of fun to watch. I had no idea a) where the O2 sensors were located and b) that they would effect idle, fuel economy and ride quality. Thanks so much for posting this!
Wife got her 2001 Chevy Silverado from her dad... whenever it is cold there was a rough idle etc and sometimes would cut off. Changes plugs and wires...fuel pump and filter.. alternator and battery.. so I let her drive my Yukon XL until I got the Chevy straight..scanned it and got the codes...was told to clean the injectors and to change the coil packs.. done...still the same problem so finally ended up getting the O2 sensor...bank 1 sensor 1. They gave me the aftermarket one..had to go back and they had 1 original fit remaining. She seems to be running fine now but I'll know in the morning when time to crank up. Thanks for the video.. really helped me. I pray this is the fix
This is exactly the video I was needing, thank you times a million for taking the time to post this. My truck is an 05 with the 5.3 and has exactly this same problem. I thought even tho the bank one sensor one was bad I might be having trouble with the plugs and wires. I had no idea that an oxygen sensor would make a vehicle run rough like that. Thanks again so much!!!
I had an 05 z71, had a po300. I didn’t have a scanner so just checked the plugs, the whole passenger side bank were fouled. Dropped the y pipe and the passenger side cat was smoked. I know on those model years the piston rings take a shit and they consume a lot of oil, it always ends up smoking the cats. Knocked out the cats and it ran great. And that was after I took it to a shop and they wanted to replace my cam lol. Needless to say I got my money back from them because they misdiagnosed it. Good video
Here’s one for you my 03 Silverado had the po300 code. I changed plugs wires and a bunch of other things and still multiple misfires. After checking the serpentine belt it was a little loose due to the tensioner. After that was replaced it was like a new vehicle!
40 seconds in, I clicked like and I subscribed. Sometimes you can just tell when someone knows what they're talking about just by how they talk about simple things
Your O2 sensors control your air/fuel ratio. If you have bad sensors your vehicle will create a "lean" condition which makes your vehicle add more fuel resulting in poor/rough idle and drastically lower your fuel economy. Not to mention you can burn out a valve or destroy your catalytic converters because they are catching all that unburnt fuel from the vehicle increasing fuel to balance what it thinks is a "lean" condition. Clean O2 sensors, Mass Air Flow Sensor, Idle Air Control Valve, and Manifold Air Pressure Sensor (if it's equipped) are a absolute must to keep that engine healthy and happy.
This was very educational and super helpful. I love that you tried to get the most helpful angle for the various steps! And seeing that other cat was helpful too.
"The hardest part of automotive repair is not swearing"? I've always told my wife that swearing was a requirement for auto repair & if you didn't swear then you probably did it wrong.
Just like you I had a P0300 so I dug into my 2010 Suburban 5.3L and found out the owner before me had installed wrong parts on the truck. They had ACdelco 6 spark plugs incorrectly gapped and copper when it should have been iridium plugs. I put the spec ones in with new wires and now no misfire.
BENT COIL CONNECTOR PIN: I had an annoying and hard to trouble shoot P0300 code on my 6 cylinder 2003 GMC Envoy XL. I had replaced the spark plugs and coils and the code and misfire would not go away. Why it did not trigger a P030x error, I don't know. Just passing this along as something simple for others to check. Have a nice day!
Great job. Thanks for being considerate enough to share your time making the video to help everyone. 👍 I'll definitely check that data when I'm checking my 03. Those sensors aren't super expensive but sure can cause headaches. Mine has the same dtc at 77k miles
I'm doing a 1999 silverado right now. P0300 code multiple misfire. Owner replaced all the plugs and coil packs and wires. Cylinders 8,6,4 aren't firing. I tried to do a compression test, both heads failed. Removed heads and found both head gaskets were bad. The owner has been driving it for a year this way. After pulling the heads I noticed those cylinders misfiring had antifoulers in them. All three were the wrong ones, causing the plugs to be bent closed. Sent the heads off, they found four bad valves. Had the heads rebuilt with new valves. Reinstalled heads and started the engine. The same cylinders are still missing. What the heck is going on!?All three look wet, so it seems they're getting fuel. I checked the coils and wires. All are working. My question to your video here is, wouldn't it throw a O2 code, rather than a Po300?
Most commonly is the bad Main engine ground at the back of the head.. Lots of people do valve jobs and say it fixted it, when it was just fixed from removing and replacing the ground on the head.
Good morning! thank you for this video it really helped me out my truck was doing the same thing it's running smoothly now, have a bless an awesome day
Thanks for your videos just bought 2007 GMC Yukon wish l had none about the engine problem l probably would not bought it has high mileage dealer said top end had been rebuilt runs great 3/2/2022 engine light came on , this is happening to old 68 dummy's at Chev dealers
Nice demo, the wrong sensor killed itself by asking for excessive fuel. Hopefully the cat survived. You could have shown off by demonstrating the fuel trim correction after the fix. I always try to think of what else could do this to one bank, the pattern was very specific.
Indeed, I dropped the ball on the post repair confirmation in the video. No signs of cat restriction or failure at the time but I would not be surprised if that was the case in the future. Im running solo at the shop since my wife is out of town and im sure you know how difficult it can be to produce a well thought out video and not forget to leave out important information when you have six cars your working on and the phone is ringing off the hook. haha, I love my job. Thank you for dropping in, I have to go get caught up on your videos as well. Blessings.
Hey Tim . For a 2005 model truck the # is 2131702 , 12587785 pre-converter and 2131699 , 12576131 downstream sensor . So , I came up with different numbers from the one you took off that truck no matter what years I searched .
My 06 gmc sierra when in park or neutral the rpm idle to 2000k and gets stuck on it until I press the break pedal any ideas why it’s doing this and what I can do to fix it?
I have an 07 silverado that threw out a po300. The first thing I did was drop the exhaust and drove it done the road with it hanging. Ran fine. Come to find out my catalytic converter on Bank 1 was clogged.
You need a magnet mount for your camera. Thanks great video. Wish I was in your town I would give you too much money to beat some of the rust off the bottom of my truck.
Well we have names for just about every vehicle model so I hope nobody takes offence. Besides, "exploder" infers that something bad happens all of the sudden. With Explorers its usually a slow painful death that takes months or years and buckets of money. hahaha Blessings!
My son’s worked on vehicles for 23 years. He loves old 68 thru 72 Ford trucks, got a restored 70. Heard him about 22 years ago call them Ford x-ploders, thought it was funny. This was around the time they were blowing all those rear tires, rolling people over. Ford blamed the tire companies, I blamed the sorry rear suspension design. A few years later, they changed the design. Mechanics that work on different vehicles know a piece of junk when they see it.
The weirdest thing is I had A P-0154 and replaced the B2S1. However, then I got a P0300 but all the misfires are on the driver's side. Along with a new Stuck 02 on B1 S1 (0-3.5MV) no response after snap. There is an exhaust manifold leak at #8. I'm wandering if someone crossed the wires on top of the motor.
Yes, I saw that. I believe it just hadn't lit off because the O2 was dead. Once I made the repairs it looked like it was back to a more normal looking downstream voltage dwell. We will have to see if it doesn't come back with a P0420 in the future. Ill follow up with him after he puts a few miles on it.
Thanks for the video . I had the same problem and it ended to be the cat. Top of the cat got broken and the powder filled up the cones so I had back pressure. I had missfire on 2,4,6 only .
I have a z71w 5.3 giving me a random misfire on multiple cylinders but no 0300 code is stored. I don't want to start throwing $ cash on things that don't fix it. It may run for days without misfiring. I changed my fueling location in case there was water in the gas, but it still randomly misfires at times. Any ideas?
Great video helped me out a lot being a female mechanic sometimes when I ask questions I just get looked at like I'm stupid yet that is not the case but I am always expected to give my knowledge when they need it and I tend to fix more problems in the shop then some of the older balding fat guys lol anyway keep up the great work I really appreciate your videos you rock
I have a 01 2500 HD with a 6 liter it has no blow by I change a PVC valve it doesn't seem to be smoking when they're driving up but when I was Towing my RV and I came to a complete stop it started blowing a lot of smoke out the exhaust he uses a quart of oil every 750 miles I'm seriously confused it runs too good to have bad rings and it has no blow-by any ideas what it could be
the 02 sensor you just removed and said doesn't look right is the exact same 02 sensor i just removed from my 2000 sierra, all 4 were exactly the same aside from the connector. unfortunately just as with the fuel injectors, plugs, coils, and wires, the 02 sensors weren't the cause of the issue. would be really nice if chevy/gmc didnt lump 50 friggin problems into one single code. if it was a ford, there would be individual codes for everything mentioned above. pretty ridiculous when they basically say "it could be literally anything in the ignition, fuel delivery, or exhaust systems. good luck!"
Hey Car Dr. Tim, I Have a 02 trailblazer that hat the p0300 / p0304 code misfire multiple cyl,i changed a coil pack in cyl 4, and vala fixed,i am wondering though if my 02 sensors are going bad to get that p0300 code? the code never came back..
I just checked mine getting cyl 4 misfire and all 3 o2s appears to work but one sit and moves between .94/.93 so this helps greatly I'm just gonna replace them all at once. Thanks man your awesome..
If it throws a misfire for a specific cylinder. Its usually a spark plug coil. Or fuel injector. If its a random misfire it can sometimes be a compression issue going on. This p0300 is a different code. I'm not for sure with thus engine. But there are different misfire codes. Not just one
@@nathangreer5741 I ended up replacing all the o2s plugs wire and coils. Runs like a brand new van the coil was the issue. Since I use it for long distance trips figured it would be safest to just do it all at once.
I have a 2004 GMC Sierra. Just rebuild the whole engine and if runs great beside a bad idle and misfire. Only when idle. Cruising is fine. Checked all plugs and wires. They all spark. Changed o2 sensors. New cats exhaust everything and I can’t seem to find what’s wrong. It’s a random misfire code P0300 but only while idiling. I’ve checked eveything but compression but it’s a brand new head that has been compression tested before it was sent out. If anyone could help I’d really appreciate it.
My '99 Silverado just threw the service engine soon light w/ the multiple cylinder misfire code stored. I'm gonna inspect the O2 sensors. But I know I do have a small intake manifold leak. Could this contribute to the light? Also, I think my cat is making a rattling noise inside. Possibly the platinum element inside is failing causing the code?
Did you get it fixed? Was it the O2sensor? I have a vacuum leak on my map sensor but now I have multiple cylinder misfires and it will also randomly throw a p0101 but I know my MAF sensor and MAP sensor are good
so i have a multiple misfire and b2s1 o2 code. the upstream passenger side sensor could cause the misfires? not sure if the misfires are on the same bank. i should have wrote them down when looking at the scan tool
You have provoked thoughts inside of my head. Im going to go and have a great day now. Have a like and rest assured knowing im gonna check my trucks O2 sensor readouts in the morning
Yes the best videos .I have a GMC Sierra pickup . after a night of rain fall.in the morning when I start my truck it misfires bad when driving Engen light flashing Los of power .but when driving for 15 minutes it goes away and doesn't come back . only if it rains any ideas? Thanks 👍🇨🇦
I changed my o2 sensors and EGR valve trying to get rid of my check engine light off. It made it worse. Now it leaks out of the exhaust pipe and turns off when I put it in reverse. 0p300 code is on and don’t know what to do next? 2001 GMA Sierra 4.8 v-thec engine. ALL ADVISE IS HELPFUL PLEASE
What codes popped up I’m having a p0300 p0101 p0455 for my gmc Sierra 1500 classic 4.3 and I’ve already replaced the distributor, rotor, MAF, fuel injectors, spark plugs, wires, tps. Still not accelerating right
Hunk a junk a truck is what I call mine lol p0300 is now what I have. Engine light now doesn't stay on. Now it comes on and flashing and stays off. Before it would come on a stay but cleared other codes. I am trying to move to AK! Love ur videos. I changed coils wires n plugs and air filter. I have black also coming out the pipe but not smoke... just dropping. Probablyfrom.bad gas i had. . I hate this please help me 😭
While i was driving i was coming to a stop and my check engine light started flashing. The truck starting running like crap. Lasted about 8 seconds and went away. I havethe p0300 code. I also have an 02 code. The 02 must definitely be causing this.
SUP Tim? Thanks for this video, I have a 2003 GMC Sierra with the P0300 multi miss fire code. I plan on applying your suggestions. I do plan on visiting Alaska and I hope I can drop by. Thanks again.
Is it common for the cylinder heads be replaced to fix a random misfire the reason I ask is I'm an auto electric tech/owner and have had customers complain about how they've been taken for a ride I have had one with a failed oil pump, lifters collapsing code was p0300 keep up the great work
I expected to find this on an old worn out O2 like is common but the find was interesting. I cant decide if being the wrong part for the application (fits an 07 and looks completely different) or if it was just defective. After replacement the fuel trims looked beautiful. Ever ran into similar?
@@ThecardoctorTV Had cases with AM crap failing like that, wired up wrong and the wrong part installed...changed out to OEM or wired it up correctly and issue resolved.
I have a 02 chevy silverado 5.3 vortec with the p0300 code light on and I don't know what could it be I have had the spark plug wires and spark plugs replaced 6 months ago so I would doubt that's the issue any help would be greatly appreciated.
I have a code p0300. I suspected O2 but my exhaust sounds loud until it warms up. If my exhaust manifold is cracked would it cause the O2 to throw a code until the manifold heated up enough to close up gap?
heres one for you 01 silverado 5.3, p0300 primarily on cyl 1&6 with some minor on 2&5, new fuel pump, wires & plugs, fuel pressure regulator, swapped coils around still same issue, o2 sensors done 2 years ago(duralast i think), smoke checked and no leaks around the intake, but a tiny leak in the egr pipe under the valve. pressure test on injectors was 31psi. im using a borrowed soulus pro and dont know what else to check, also it only misfires around 1800-2200 rpm, no misfires at idle.
@@ThecardoctorTV new muffler slightly smaller body diameter (walker) original exhaust, no noticeable loss of power under load, gonna check the o2 sensor numbers again tomorrow,
@@remiel3315 I’ve had several where the fuel pump began to fail and pumped carbon into injectors and caused subsequent misfires. If yours has a filter it would be worth removing and sampling fuel.
@@ThecardoctorTV new filter and lines in 2022, replaced filter again thinking the same thing last month, new fuel pump 2 weeks ago (delphi) old one was an Carter aftermarket and was on it's way out
Upstream o2 look ok, 50-700mv down stream don't, b1s2 45mv avg, b2s2 700mv avg, also my egr position % stays at 0 and the egr is not stuck, ran the test on the solus(still learning how to) and no position change, removed and inspected, no visible leaks, clogs, but no movement when engine is running
Can a faulty CMP sensor be the reason for my P0206 & P0306? NOID light won’t light on #6 connector....the wires look fine and are testing the proper voltage....so it’s either the ECU or maybe the CMP. I’m trying to find a cut and dry answer to my question. CAN A FAULTY CMP sensor cause only one injector from pulsing? Or would it cause all of them to act up? Please any information is appreciated
I have the same issue with my 02 suburban, getting bank 1 sensor 1. Have tried 4 different sensors from the parts store and still getting the code and rough idles.. Any ideas? Throwing P0300, P001B and the same 02 sensors codes..
Snap On Solus Edge isn't in production anymore, but you can pick a new one up on eBay for around $1.7k. The newer Solus Legend sold by Snap On has an MSRP of $3295.00.
Hi Tim I just subscribed to your channel and also bookmarked your video. I am from CA. I just a have Service Engine Soon light came on a couple of weeks ago when my vehicle started running rough or hesitate only when the engine is cold. After my vehicle warms up and driving everything runs fine. I have a 2001 GMC Sierra 1500 V8-5.3L with a P-Code P0300 random missed fire. I am about to replace the spark plug with ACDELCO brand from Autozone tomorrow morning. Should I also look into replacing the O2S sensors? I replaced all the spark wires 2/3/2016 and I believe also replace the spark plug at the same time frame. I have done a major repair on my truck replacing knock sensors (both). All gasket has been repair it took me and my brother about 1 whole month to do a major repair and replace everything include the water pump all. My truck has broken exhaust manifold engine bolts so we replace all of that too. There are three bolts that broken off so it is too difficult to drill it out so we end up using Kraft exhaust manifold clamp repairt kit to hold it the cylinder head leak together and that made it work. I found the kraft manifold clamp on the drive which is pretty hard to get to was pretty loose. I was able to tighten and was hope that this might the trick but the service engine soon would not go away so I went Autozone and was able to erase the P0300 code. The service engine soon light went away but engine still running a bit rough not as much but I am pretty sure the service engine soon will surface again. Can you shed some light?
I’ve got an 04 Silverado with a 5.3. I’m getting a P0300 and previously a P0440. No rough idle or black smoke. No performance issues. When I get up to about 70mph, the check engine will start flashing and then stay on when I slow down. Again, no performance issues. At one point, the dash told me to replace the gas cap which I did. I installed new plugs and wires yesterday. I drove to work and scanned it. It’s got a P0300 “pre” fail code, but no CEL yet. Any ideas?
Probably did the old trick with putting a gallon of paint thinner in a nearly full tank of gas and driving till the tank was gone and then full the tank up again with out the paint thinner and drive back burning the full tank again.
Love the video and the amount of detail you provide! Thank you! Too bad you don't have a pair of those "Google Glasses" to record the videos with. I'm pretty sure they're no longer available due to security issues and liability for Google. You did a great job of recording none the less! Most videos I see don't have nearly as much detail as yours does.
You are not a fat, old, balding guy who is losing his mind. You are an experienced, distinguished, full sized car repair artist. Always enjoy your videos
****Blushing**** :)
@@ThecardoctorTV I have a 2000 Chevy half ton 5.3 l that stumbling around showing p0300 multiple misfires I also have a code in the computer Bank 1 and 2 we're not working on the oxygen sensors. So O2 sensors will call these these trucks to stumble real bad like they're misfiring?
@@brt-jn7kg t
@@brt-jn7kg the o2 sensors measure the oxygen as you can imagine. So the truck and give the right air to fuel ratio. If they are not working then your engine doesn’t know how much fuel to send
You forgot to mention the Cat 🐈 like Reflexes 👍
Great heads up!!!!
A buddy and myself pulled an 09 denali 6.0 that had oil leaks everywhere. When we installed it and finished it off it was running terrible (on odd bank) and we werent sure why... P0304. We went after # 4 no coil operation. Checked fuses power supply etc.
Found it was the whole bank out. I figured I would google it ( yeah right! Who else has had this problem...nobody)
Your video popped right up.
It saved me hours of diag time. Went right to it found a broken wire, fixed it, cleaned and tightened the ground....Done!
Thank You for putting this out.
When you dont have a scanner or wire schematics life can suck.
You helped me avoid the suck.
I have watched just three of your videos after finding you on TH-cam and all three vids fixed the problem I was having. Thank you ever so much for blowing up my parts cannon. You rock Tim!
'...and you burn yourself just like that...' I finally found this video on the goose chase of fixing my p0300 trouble on an '01 Silverado. This was a very helpful video and a lot of fun to watch. I had no idea a) where the O2 sensors were located and b) that they would effect idle, fuel economy and ride quality. Thanks so much for posting this!
Wife got her 2001 Chevy Silverado from her dad... whenever it is cold there was a rough idle etc and sometimes would cut off. Changes plugs and wires...fuel pump and filter.. alternator and battery.. so I let her drive my Yukon XL until I got the Chevy straight..scanned it and got the codes...was told to clean the injectors and to change the coil packs.. done...still the same problem so finally ended up getting the O2 sensor...bank 1 sensor 1. They gave me the aftermarket one..had to go back and they had 1 original fit remaining. She seems to be running fine now but I'll know in the morning when time to crank up. Thanks for the video.. really helped me. I pray this is the fix
Did it fix it? I'm having the similar issue. I really don't want to mess with the fuel injectors
This is exactly the video I was needing, thank you times a million for taking the time to post this. My truck is an 05 with the 5.3 and has exactly this same problem. I thought even tho the bank one sensor one was bad I might be having trouble with the plugs and wires. I had no idea that an oxygen sensor would make a vehicle run rough like that. Thanks again so much!!!
Me to!!!!!!!!!!
If it helps I had the same problem but it was plugs and because of this the wires and coil was replaced with 100% problem solved.
I had an 05 z71, had a po300. I didn’t have a scanner so just checked the plugs, the whole passenger side bank were fouled. Dropped the y pipe and the passenger side cat was smoked. I know on those model years the piston rings take a shit and they consume a lot of oil, it always ends up smoking the cats. Knocked out the cats and it ran great. And that was after I took it to a shop and they wanted to replace my cam lol. Needless to say I got my money back from them because they misdiagnosed it. Good video
Here’s one for you my 03 Silverado had the po300 code. I changed plugs wires and a bunch of other things and still multiple misfires. After checking the serpentine belt it was a little loose due to the tensioner. After that was replaced it was like a new vehicle!
40 seconds in, I clicked like and I subscribed. Sometimes you can just tell when someone knows what they're talking about just by how they talk about simple things
Not sure if it will solve my problem, but this this is the best repair video i have ever watched. Kudos
This gentleman would be perfect as an in person teacher also. Someone who wouldn’t make you feel dumb for asking questions.
Your O2 sensors control your air/fuel ratio. If you have bad sensors your vehicle will create a "lean" condition which makes your vehicle add more fuel resulting in poor/rough idle and drastically lower your fuel economy. Not to mention you can burn out a valve or destroy your catalytic converters because they are catching all that unburnt fuel from the vehicle increasing fuel to balance what it thinks is a "lean" condition. Clean O2 sensors, Mass Air Flow Sensor, Idle Air Control Valve, and Manifold Air Pressure Sensor (if it's equipped) are a absolute must to keep that engine healthy and happy.
This was very educational and super helpful. I love that you tried to get the most helpful angle for the various steps! And seeing that other cat was helpful too.
"The hardest part of automotive repair is not swearing"? I've always told my wife that swearing was a requirement for auto repair & if you didn't swear then you probably did it wrong.
If that's true then I almost always do things right! haha,
Mechanic started out when I was a Lil squirt. And till now I still swear every time I do a car 🤣😂🤣
@@ThecardoctorTV yep we all do lmao. Hey guys I finally found where the real mechanics hang out lmao
Thats how i do it. Have to use a few swear words. A few busted knuckles.
😂 my dad was a mechanic and work on the cars at home there was a whole lot of gd's
Just like you I had a P0300 so I dug into my 2010 Suburban 5.3L and found out the owner before me had installed wrong parts on the truck. They had ACdelco 6 spark plugs incorrectly gapped and copper when it should have been iridium plugs. I put the spec ones in with new wires and now no misfire.
Currently I have only a P0300 with check engine light and bad idle. What do you think?
@@nazareta6541 shop out the right spark plugs. you can do it yourself in an hour. Mine runs great now and the light is still off.
Tim I might have suggested pulling bank 2 o/2 just to see if it was or wasn’t the right one before tightening it .
I would use your shop if it wasn't such a drive...do appreciate your advice.Knowledge through experience is unbeatable.
BENT COIL CONNECTOR PIN: I had an annoying and hard to trouble shoot P0300 code on my 6 cylinder 2003 GMC Envoy XL. I had replaced the spark plugs and coils and the code and misfire would not go away. Why it did not trigger a P030x error, I don't know. Just passing this along as something simple for others to check. Have a nice day!
Great find! Thank you for sharing the fix!
Great job. Thanks for being considerate enough to share your time making the video to help everyone. 👍 I'll definitely check that data when I'm checking my 03. Those sensors aren't super expensive but sure can cause headaches. Mine has the same dtc at 77k miles
Best video I’ve watched. Honest man that truly wants to help. Subscribed!
I'm doing a 1999 silverado right now. P0300 code multiple misfire. Owner replaced all the plugs and coil packs and wires. Cylinders 8,6,4 aren't firing. I tried to do a compression test, both heads failed. Removed heads and found both head gaskets were bad. The owner has been driving it for a year this way. After pulling the heads I noticed those cylinders misfiring had antifoulers in them. All three were the wrong ones, causing the plugs to be bent closed. Sent the heads off, they found four bad valves. Had the heads rebuilt with new valves. Reinstalled heads and started the engine. The same cylinders are still missing. What the heck is going on!?All three look wet, so it seems they're getting fuel. I checked the coils and wires. All are working. My question to your video here is, wouldn't it throw a O2 code, rather than a Po300?
Most commonly is the bad Main engine ground at the back of the head.. Lots of people do valve jobs and say it fixted it, when it was just fixed from removing and replacing the ground on the head.
Good morning! thank you for this video it really helped me out my truck was doing the same thing it's running smoothly now, have a bless an awesome day
Thanks for your videos just bought 2007 GMC Yukon wish l had none about the engine problem l probably would not bought it has high mileage dealer said top end had been rebuilt runs great 3/2/2022 engine light came on , this is happening to old 68 dummy's at Chev dealers
Reminds me of my dad they way you work and explain and talk, and thanks for the video, I never knew o2 sensor shows misfire code. 🙏
i love how you said you will choose to have a great day! Ur a awesome mechanic!
I’m here to watch the best videos on YT and I just so happen to have this P0300 code on my truck. What a coincidence.
Nice demo, the wrong sensor killed itself by asking for excessive fuel. Hopefully the cat survived. You could have shown off by demonstrating the fuel trim correction after the fix. I always try to think of what else could do this to one bank, the pattern was very specific.
Indeed, I dropped the ball on the post repair confirmation in the video. No signs of cat restriction or failure at the time but I would not be surprised if that was the case in the future. Im running solo at the shop since my wife is out of town and im sure you know how difficult it can be to produce a well thought out video and not forget to leave out important information when you have six cars your working on and the phone is ringing off the hook. haha, I love my job. Thank you for dropping in, I have to go get caught up on your videos as well. Blessings.
My 08 silverado just hit 200k along with that came this p0300 code. I have the rough idle for sure. Was thinking bout o2 sensor.
TrendKill Will probably the plugs and wires and have seen many times the o2 sensor wires rip open and rub onto the frame
Hey Tim . For a 2005 model truck the # is 2131702 , 12587785 pre-converter and 2131699 , 12576131 downstream sensor . So , I came up with different numbers from the one you took off that truck no matter what years I searched .
My 06 gmc sierra when in park or neutral the rpm idle to 2000k and gets stuck on it until I press the break pedal any ideas why it’s doing this and what I can do to fix it?
I have an 07 silverado that threw out a po300. The first thing I did was drop the exhaust and drove it done the road with it hanging. Ran fine. Come to find out my catalytic converter on Bank 1 was clogged.
Thanks for the video. Turns out my 07 silverado 4.3 o2 sensor b2s2 bad voltage and barely moving
You need a magnet mount for your camera. Thanks great video. Wish I was in your town I would give you too much money to beat some of the rust off the bottom of my truck.
Ford “Exploder”. A buddy of mine had an Exploder that he called his this term. I had never heard that before he used it one day.
Well we have names for just about every vehicle model so I hope nobody takes offence. Besides, "exploder" infers that something bad happens all of the sudden. With Explorers its usually a slow painful death that takes months or years and buckets of money. hahaha Blessings!
My son’s worked on vehicles for 23 years. He loves old 68 thru 72 Ford trucks, got a restored 70. Heard him about 22 years ago call them Ford x-ploders, thought it was funny. This was around the time they were blowing all those rear tires, rolling people over. Ford blamed the tire companies, I blamed the sorry rear suspension design. A few years later, they changed the design. Mechanics that work on different vehicles know a piece of junk when they see it.
Still relevant. Glad I found this video today.
Man I love this dudes whole vibe!! Keep up the good work
The weirdest thing is I had A P-0154 and replaced the B2S1.
However, then I got a P0300 but all the misfires are on the driver's side.
Along with a new Stuck 02 on B1 S1
(0-3.5MV) no response after snap.
There is an exhaust manifold leak at #8.
I'm wandering if someone crossed the wires on top of the motor.
"The best videos on TH-cam". ✊
Rock on, brother, rock on.
Lol I just came for the best videos on the internet, but the info is appreciated 😄👍
Tim you rock ! Much love all the way from Cincinnati Oh
Great video! I did notice that the Bank 1 downstream O2 was switching like you may have a bad converter.
Yes, I saw that. I believe it just hadn't lit off because the O2 was dead. Once I made the repairs it looked like it was back to a more normal looking downstream voltage dwell. We will have to see if it doesn't come back with a P0420 in the future. Ill follow up with him after he puts a few miles on it.
That was awesome I learned something I have a Yukon 2000 similar as what you're doing to it now thank you I love it your video
Thanks for the video .
I had the same problem and it ended to be the cat. Top of the cat got broken and the powder filled up the cones so I had back pressure. I had missfire on 2,4,6 only .
I have a z71w 5.3 giving me a random misfire on multiple cylinders but no 0300 code is stored.
I don't want to start throwing $ cash on things that don't fix it.
It may run for days without misfiring.
I changed my fueling location in case there was water in the gas, but it still randomly misfires at times.
Any ideas?
Injectors.
Run some good quality injector cleaner with high octane fuel before considering injector replacements.
Great video helped me out a lot being a female mechanic sometimes when I ask questions I just get looked at like I'm stupid yet that is not the case but I am always expected to give my knowledge when they need it and I tend to fix more problems in the shop then some of the older balding fat guys lol anyway keep up the great work I really appreciate your videos you rock
Good video, but did the o2 sensor fixed the problem, because you stated that you were doing a crank sensor relearn
I have a 01 2500 HD with a 6 liter it has no blow by I change a PVC valve it doesn't seem to be smoking when they're driving up but when I was Towing my RV and I came to a complete stop it started blowing a lot of smoke out the exhaust he uses a quart of oil every 750 miles I'm seriously confused it runs too good to have bad rings and it has no blow-by any ideas what it could be
the 02 sensor you just removed and said doesn't look right is the exact same 02 sensor i just removed from my 2000 sierra, all 4 were exactly the same aside from the connector. unfortunately just as with the fuel injectors, plugs, coils, and wires, the 02 sensors weren't the cause of the issue. would be really nice if chevy/gmc didnt lump 50 friggin problems into one single code. if it was a ford, there would be individual codes for everything mentioned above. pretty ridiculous when they basically say "it could be literally anything in the ignition, fuel delivery, or exhaust systems. good luck!"
Hey Car Dr. Tim, I Have a 02 trailblazer that hat the p0300 / p0304 code misfire multiple cyl,i changed a coil pack in cyl 4, and vala fixed,i am wondering though if my 02 sensors are going bad to get that p0300 code? the code never came back..
Just wanted to say Thank You!!
Very helpful. 👍🏽
I just checked mine getting cyl 4 misfire and all 3 o2s appears to work but one sit and moves between .94/.93 so this helps greatly I'm just gonna replace them all at once. Thanks man your awesome..
If it throws a misfire for a specific cylinder. Its usually a spark plug coil. Or fuel injector. If its a random misfire it can sometimes be a compression issue going on. This p0300 is a different code.
I'm not for sure with thus engine. But there are different misfire codes. Not just one
@@nathangreer5741 I ended up replacing all the o2s plugs wire and coils. Runs like a brand new van the coil was the issue. Since I use it for long distance trips figured it would be safest to just do it all at once.
Hahaha, not cussing is always the hardest part when I'm working on a vehicle ;)
😂😂😂 agreed
I have a 2004 GMC Sierra. Just rebuild the whole engine and if runs great beside a bad idle and misfire. Only when idle. Cruising is fine. Checked all plugs and wires. They all spark. Changed o2 sensors. New cats exhaust everything and I can’t seem to find what’s wrong. It’s a random misfire code P0300 but only while idiling. I’ve checked eveything but compression but it’s a brand new head that has been compression tested before it was sent out. If anyone could help I’d really appreciate it.
It is one of the best channels.
My '99 Silverado just threw the service engine soon light w/ the multiple cylinder misfire code stored. I'm gonna inspect the O2 sensors. But I know I do have a small intake manifold leak. Could this contribute to the light? Also, I think my cat is making a rattling noise inside. Possibly the platinum element inside is failing causing the code?
Did you get it fixed? Was it the O2sensor? I have a vacuum leak on my map sensor but now I have multiple cylinder misfires and it will also randomly throw a p0101 but I know my MAF sensor and MAP sensor are good
so i have a multiple misfire and b2s1 o2 code. the upstream passenger side sensor could cause the misfires? not sure if the misfires are on the same bank. i should have wrote them down when looking at the scan tool
You have provoked thoughts inside of my head. Im going to go and have a great day now. Have a like and rest assured knowing im gonna check my trucks O2 sensor readouts in the morning
What’s the name of that scan tool that you have
sooo.... a failing o2 can cause misfire???
9:00 needs more cowbell...
Yes the best videos .I have a GMC Sierra pickup . after a night of rain fall.in the morning when I start my truck it misfires bad when driving Engen light flashing Los of power .but when driving for 15 minutes it goes away and doesn't come back . only if it rains any ideas? Thanks 👍🇨🇦
Mine misses in the rain too
That was very helpful, thnx from Texas
I changed my o2 sensors and EGR valve trying to get rid of my check engine light off.
It made it worse. Now it leaks out of the exhaust pipe and turns off when I put it in reverse.
0p300 code is on and don’t know what to do next? 2001 GMA Sierra 4.8 v-thec engine.
ALL ADVISE IS HELPFUL PLEASE
Thank you now I get to buy my dream truck and willl be able to easily fix it
Why was the oxygen sensor caked up with carbon? Bad mass air flow sensor making it run rich?? Or clogged air filter??
Ford exploder love it , great video thanks car dr.
What codes popped up I’m having a p0300 p0101 p0455 for my gmc Sierra 1500 classic 4.3 and I’ve already replaced the distributor, rotor, MAF, fuel injectors, spark plugs, wires, tps. Still not accelerating right
I get the code when I'm on the highway but it don't run ruff just light comes on on the highway
Hunk a junk a truck is what I call mine lol p0300 is now what I have. Engine light now doesn't stay on. Now it comes on and flashing and stays off. Before it would come on a stay but cleared other codes. I am trying to move to AK! Love ur videos. I changed coils wires n plugs and air filter. I have black also coming out the pipe but not smoke... just dropping. Probablyfrom.bad gas i had. . I hate this please help me 😭
While i was driving i was coming to a stop and my check engine light started flashing. The truck starting running like crap. Lasted about 8 seconds and went away. I havethe p0300 code. I also have an 02 code. The 02 must definitely be causing this.
SUP Tim? Thanks for this video, I have a 2003 GMC Sierra with the P0300 multi miss fire code. I plan on applying your suggestions. I do plan on visiting Alaska and I hope I can drop by. Thanks again.
Thanks pal... saved me a bundle of headaches!! Wade
Excellent
Is it common for the cylinder heads be replaced to fix a random misfire the reason I ask is I'm an auto electric tech/owner and have had customers complain about how they've been taken for a ride I have had one with a failed oil pump, lifters collapsing code was p0300 keep up the great work
Great video. Exact problem with a 2004 Silverado 2500HD.
did you ever fix it?
That part number from the older oxygen sensor is for or fits 03-05 up too 2011 silerado,tahoe,suburban 323 cu. 5.3 V8... 0m0s6027-213-1702
Downstream pigtail is different ,good video.
Nice diag & repair Tim! Yea they don't work so well when they're clogged up.
I expected to find this on an old worn out O2 like is common but the find was interesting. I cant decide if being the wrong part for the application (fits an 07 and looks completely different) or if it was just defective. After replacement the fuel trims looked beautiful. Ever ran into similar?
@@ThecardoctorTV Had cases with AM crap failing like that, wired up wrong and the wrong part installed...changed out to OEM or wired it up correctly and issue resolved.
I have a 02 chevy silverado 5.3 vortec with the p0300 code light on and I don't know what could it be I have had the spark plug wires and spark plugs replaced 6 months ago so I would doubt that's the issue any help would be greatly appreciated.
He said bong. 420 time. You are the man.
I have a code p0300. I suspected O2 but my exhaust sounds loud until it warms up. If my exhaust manifold is cracked would it cause the O2 to throw a code until the manifold heated up enough to close up gap?
heres one for you 01 silverado 5.3, p0300 primarily on cyl 1&6 with some minor on 2&5, new fuel pump, wires & plugs, fuel pressure regulator, swapped coils around still same issue, o2 sensors done 2 years ago(duralast i think), smoke checked and no leaks around the intake, but a tiny leak in the egr pipe under the valve. pressure test on injectors was 31psi. im using a borrowed soulus pro and dont know what else to check, also it only misfires around 1800-2200 rpm, no misfires at idle.
Clogged exhaust?
@@ThecardoctorTV new muffler slightly smaller body diameter (walker) original exhaust, no noticeable loss of power under load, gonna check the o2 sensor numbers again tomorrow,
@@remiel3315 I’ve had several where the fuel pump began to fail and pumped carbon into injectors and caused subsequent misfires. If yours has a filter it would be worth removing and sampling fuel.
@@ThecardoctorTV new filter and lines in 2022, replaced filter again thinking the same thing last month, new fuel pump 2 weeks ago (delphi) old one was an Carter aftermarket and was on it's way out
Upstream o2 look ok, 50-700mv down stream don't, b1s2 45mv avg, b2s2 700mv avg, also my egr position % stays at 0 and the egr is not stuck, ran the test on the solus(still learning how to) and no position change, removed and inspected, no visible leaks, clogs, but no movement when engine is running
I have an 02 sierra 2500hd with a 6.0 that's throwing p0300 only when it idles. I found a vaccum leak and it's running better but still not right
Lots of possibilities. Vacuum leaks. Ignition misfires. Clogged injectors. Injector wiring issues. Needing a CMP/CKP learn. Etc.
Nice video Tim. I hope all is well
Thank you Jim. Going well here. Hope you are also good. Blessings.
Thank for showing me I had that p0300 and it was bank 1 sensor 2 the tip was gone.
Knock sensors
P0300 means : Needle in a hay stack.
So not having O2 sensor connected could be my misfire on my k1500 I don't have my O2 sensor connected so I have that code and the misfire
Can a faulty CMP sensor be the reason for my P0206 & P0306? NOID light won’t light on #6 connector....the wires look fine and are testing the proper voltage....so it’s either the ECU or maybe the CMP. I’m trying to find a cut and dry answer to my question. CAN A FAULTY CMP sensor cause only one injector from pulsing? Or would it cause all of them to act up? Please any information is appreciated
Yes you do love to help. I've seen it first hand.
I have misfire on my 07 Yukon I repaired engine coils and plugs still run rough
I have the same issue with my 02 suburban, getting bank 1 sensor 1. Have tried 4 different sensors from the parts store and still getting the code and rough idles.. Any ideas? Throwing P0300, P001B and the same 02 sensors codes..
Awesome Video that looks like an amazing scanner...Saw it said snap-on afraid to ask how much that little doo hickey costs
Snap On Solus Edge isn't in production anymore, but you can pick a new one up on eBay for around $1.7k.
The newer Solus Legend sold by Snap On has an MSRP of $3295.00.
Hi Tim I just subscribed to your channel and also bookmarked your video. I am from CA. I just a have Service Engine Soon light came on a couple of weeks ago when my vehicle started running rough or hesitate only when the engine is cold. After my vehicle warms up and driving everything runs fine. I have a 2001 GMC Sierra 1500 V8-5.3L with a P-Code P0300 random missed fire. I am about to replace the spark plug with ACDELCO brand from Autozone tomorrow morning. Should I also look into replacing the O2S sensors? I replaced all the spark wires 2/3/2016 and I believe also replace the spark plug at the same time frame. I have done a major repair on my truck replacing knock sensors (both). All gasket has been repair it took me and my brother about 1 whole month to do a major repair and replace everything include the water pump all. My truck has broken exhaust manifold engine bolts so we replace all of that too. There are three bolts that broken off so it is too difficult to drill it out so we end up using Kraft exhaust manifold clamp repairt kit to hold it the cylinder head leak together and that made it work. I found the kraft manifold clamp on the drive which is pretty hard to get to was pretty loose. I was able to tighten and was hope that this might the trick but the service engine soon would not go away so I went Autozone and was able to erase the P0300 code. The service engine soon light went away but engine still running a bit rough not as much but I am pretty sure the service engine soon will surface again.
Can you shed some light?
I’ve got an 04 Silverado with a 5.3. I’m getting a P0300 and previously a P0440. No rough idle or black smoke. No performance issues. When I get up to about 70mph, the check engine will start flashing and then stay on when I slow down. Again, no performance issues. At one point, the dash told me to replace the gas cap which I did. I installed new plugs and wires yesterday. I drove to work and scanned it. It’s got a P0300 “pre” fail code, but no CEL yet. Any ideas?
th-cam.com/video/2gJpG3fHXlg/w-d-xo.html
Did you fix this? I have the same issue
@@NEfishingtales yes. It needed a reflash. I took it to a neighborhood mechanic. It maybe 15 minutes.
What is a reflash
Probably did the old trick with putting a gallon of paint thinner in a nearly full tank of gas and driving till the tank was gone and then full the tank up again with out the paint thinner and drive back burning the full tank again.
Love the video and the amount of detail you provide! Thank you! Too bad you don't have a pair of those "Google Glasses" to record the videos with. I'm pretty sure they're no longer available due to security issues and liability for Google. You did a great job of recording none the less! Most videos I see don't have nearly as much detail as yours does.
Why are the sensors so clean what are you doing?
Excellent video. Thanks for sharing!
If it’s in open loop then you cannot determine those sense values Until you’re in closed loop
My trucks start missing but it doesn't miss all the times helping please
Love to come to Alaska and see you and have a beer, thanks for your knowledge
I'm here to watch the best videos 👍👍
Thank you definitely going to try this